H_2S gas,when passed through a solution conta | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) $H_2S$ is a weak electrolyte and undergoes dissociation as: $H_2S \rightleftharpoons 2H^+ + S^{2-}$.According to the common ion effect,the presenc

Vedclass · Accepted Answer

Presence of $HCl$ decreases the sulphide ion concentration

Vedclass · Answer

(A) $H_2S$ is a weak electrolyte and undergoes dissociation as: $H_2S \rightleftharpoons 2H^+ + S^{2-}$.According to the common ion effect,the presence of $HCl$ (a strong electrolyte) provides a high concentration of $H^+$ ions.This suppresses the ionization of $H_2S$,thereby significantly decreasing the concentration of $S^{2-}$ ions.The solubility product $(K_{sp})$ of group $II$ sulphides is very low,so even a low concentration of $S^{2-}$ is sufficient to exceed the ionic product and cause precipitation.However,the $K_{sp}$ of group $IV$ sulphides is relatively higher,and the suppressed $S^{2-}$ concentration is insufficient to cause their precipitation.

$H_2S$ gas,when passed through a solution containing $HCl$,precipitates the cations of group $II$ of qualitative analysis but not those belonging to the fourth group. This is because:

Similar Questions

The solubility of $AgI$ in $NaI$ is less than that in pure water because ................

The solubility of $AgBr$ is minimum in:

When $H_2S$ gas is passed through a solution containing $HCl$ during qualitative analysis,cations of the second group are precipitated,but cations of the fourth group are not precipitated because:

Which of the following will not have its ionization suppressed by the addition of $HCl$?

In the precipitation of the iron group $(III)$ in qualitative analysis,ammonium chloride is added before adding ammonium hydroxide to :

Vedclass Test Series

Exam Paper Generator

Online Exam Module